LINCOLN SQUARE — The annual two-day architecture-palooza known as Open House Chicago offers a behind-the-scenes pass to more than 200 architectural treasures across the city, including several right in Lincoln Square's back yard.

Seven sites in Lincoln Square/Ravenswood are taking part in the 2017 fest, set for Oct. 14-15, from perennial fan favorites like the Airstream — It's an RV! On a roof! — to Half Acre's brand spanking new Balmoral Tap Room.

Here's the local lineup, no tickets required, free admission:

• The Airstream, 1807 W. Sunnyside Ave.; open 10 a.m. to 5 p.m. both days of the fest.

This rooftop RV is more or less a break room for employees of Chicago Associates Planners and Architects. Makes your work place kitchenette seem kind of sad, no?

Part printmaking studio, part art gallery, the collaborative settled into new digs in 2015 after a complete gut renovation of the interior of the building on Western Avenue. Demonstrations of printmaking techniques are always a highlight of Open House weekend.

Half Acre's newly opened Balmoral Tap Room has been getting a lot of attention lately but the brewery itself, with its massive bow-truss ceiling and gleaming steel brewing equipment, is something to see as well.

Brown Line riders will recognize the building's arched atrium roof, visible in the distance as trains make their way between Belmont and Western. The history of this architectural feature is fascinating: The event center was once a billboard factory, and the atrium allowed craftsmen to paint under natural light. The building now also houses a vintage car collection.